The present invention relates generally to illumination devices. It finds particular application in conjunction with illumination devices employing multiple light emitting diodes (“LEDs”) and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other like applications.
Most automotive lamps use incandescent filaments to generate light. The light can be reflected off a simple mirror-type reflector. LEDs have been replacing incandescent filaments as a light source, because LEDs are more efficient and longer lasting.
LEDs are small efficient light sources, but to emit a sufficient amount of light, especially in an automotive lamp, a plurality of LEDs need to be grouped together. Pointing the LEDs toward the field where illumination is desired can appear to an onlooker as a group of bright dots. A reflector is provided in the lamp to direct and scatter the light so that the lamp does not look like a plurality of lighted dots.
LEDs operate at high temperatures. High operating temperatures degrade the performance of LED lighting systems. Also, high-powered LEDs can have very wide light emission angles, some approaching or exceeding 180°. Existing LED reflector/thermal systems either collect a much smaller cone angle of light or fail to provide a thermal path for heat convection.
Accordingly, it is desirable to design a lamp that collects the majority of light emitted by an LED and directs it toward a desired target. It is also desirable to position the LED such that light reflected by the reflector does not strike the LED resulting in additional heat being directed toward the LED. It is also desirable to provide a suitable thermal path for cooling the lamp.